1. Field of the Invention
The invention is directed to a crane with a telescoping boom whose sections are arranged in a base boom and that can telescope in and out individually, by a hydraulic piston-cylinder unit after disengaging locking pin connections. The sections are secured in the respective moved out or moved in positions by locking pins. A piston rod of the piston-cylinder unit is articulated by its rear end to the inner end of the base boom, and a safety locking unit connectable to recesses in the telescoping sections is fastened to the inner end and outer end of a displaceable cylinder housing, and a guide profile head is arranged at a remote end of the articulation of the safety locking unit to the inner end of the base boom.
2. Prior Art
A crane of the type mentioned above is known from EP 0 984 895 B1.
In practice, main booms with a length of 50 meters can be realized.
DE 10 2006 023 371 A1 discloses a head piece of a final boom section be constructed such that additional boom sections can be inserted through this head piece so that all of the sections can achieve greater boom lengths when telescoping, for example, a twofold increase to 100 meters.